In his previous three games, the combative London Knights forward piled up four 10-minute misconducts.

Two were for mouth-guard violations.

Another was for mouthing off.

The fourth, in Brampton on Sunday, was because the tie-down on the back of jersey came undone during a fight.

These constant half-period sit-downs have become a major problem for the Knights.

Rinaldo is the centre on the club's most effective forward line.

When he's not in the box, the Philly Flyers prospect is skilled at killing penalties.

The Knights need him on the ice, not cooling off in the dressing room or rotting in the sin bin.

"We don't want Zac sitting in the penalty box 10 minutes at a time," London assistant coach Jacques Beaulieu said, "especially for something that is under our control."

The mouth guard business isn't a new irritant. Rinaldo got caught for it way back on Oct. 9 against the Plymouth Whalers.

He said he usually shifts it back and forth in his mouth. It's never been comfortable for him to wear.

He has a quick gag reflex.

Problem is, the officials are looking to enforce it.

According to the OHL 2009-10 rule book, "all players must properly wear a full coloured dentist fabricated mouth guard that covers the back molar teeth."

A coach or player can bring an infraction to the ref's attention. If it is noticed before the play, a misconduct is assessed immediately. If it's worn improperly during play, the misconduct comes at the next whistle.

"I didn't like wearing a mouth guard as a player, either," Beaulieu said, "but you still wore it. The officials are looking to enforce that penalty and Zac is well-known to the refs in this league."

Rinaldo has never blended into the background.

He led the OHL in penalty minutes last season.

He's the frontrunner again this year with 79, although the league doesn't include 10-minute misconducts when adding up their totals.

The Knights have talked to Rinaldo about the mouth guard business.

"You have to wear it," London GM Mark Hunter said. "That's the rule. You can say there are guys on other teams who aren't wearing them properly but the onus is on us to make sure the London Knights are wearing them right."

If the OHL enforced that penalty when Pat Kane played for the Knights, he would never have scored 62 goals in 2006-07.

He was constantly chewing on his mouth guard. He would've dwarfed Rinaldo's violations.

Heck, Kane's on the cover of EA Sports' NHL '10 video game with the mouth guard hanging out. That's a 10-minute misconduct in the OHL.

It may leave a bittersweet taste on Rinaldo's tongue, but he has too much to lose.

He'll get a chance to show what he can do with the OHL team in the Canada-Russia Subway Super Series Nov. 23 in Windsor.

His goal is to make the Canadian world junior team in Decemeber, but there's zero chance Hockey Canada risks a sixth-straight gold medal on a guy who might take a terrible penalty at the wrong time.

The Knights don't fault Rinaldo for his tie-down coming undone.

That was, in the infamous words of Justin Timberlake's press agent, a "wardrobe malfunction." Beaulieu said the loop on Rinaldo's pants broke.

Former London trainer Don Brankley said he always checked his players' jerseys before going on the ice to make sure the tie-downs were affixed to avoid an infraction.